Abstract
Purpose: :
The goal of this work was to quantify macular function in atrophic and exudative age-related macular degeneration (AMD) by correlating psychophysical and electrophysiological measures with macular thickness.
Methods: :
Twenty-eight AMD patients with CNV in one eye (exudative AMD group: n=28 eyes; mean age: 76,96 + 5,73 years) and drusen and/or RPE changes without CNV or geographic atrophy in the fellow eye (atrophic AMD group: n=28 eyes; mean age: 76,96 + 5,73 years) were included in the study and compared with a control age-matched group. Macular function was tested by using multifocal electroretinogram (mfERG) and microperimetry, and macular thickness was determined by optical coherence tomography (OCT). Statistical analysis was performed using ANOVA at a significance level of p< 0,05.
Results: :
We have found a significant delay in implicit time for all mfERG rings in atrophic (R1 p=0,0242; R2 p=0,0287; R3 p=0,0054) and exudative AMD (R1 p=0,0062; R2 and R3 p<0,0001). Patients with exudative AMD have also significant reduction in P1 amplitude (R1 p=0,0488; R2 p=0,0107; R3 p=0,0212). We have found a decreased retinal function in both clinical forms by using microperimetry (p<0,0001). Morphometric results showed a significant increase in macular thickness in ring 1 for exudative AMD (p=0,0135). Interestingly, we have found that macular thickness is not correlated with measures of functional impairment. We found a significant correlation between P1 amplitude and microperimetric results (R=0,584 p=0,0024) for exudative AMD.
Conclusions: :
Morphometric and functional data provide independent information on the clinical status of both atrophic and exsudative AMD. The lack of correlation between both types of measure possibly reflects the fact that changes also occur in non-neural structures. The correlation between physiological measures, suggests that microperimetry and mfERG are partially testing the same neural correlates.
Keywords: age-related macular degeneration • electroretinography: clinical • neovascularization